Air-cooled muffler



Aug. 28, 1928.

E. P. GRAY AIR COOLED MUFFLER Filed May 8, 1926 2 Sheets-Sheet 1 INVENTOR. [M157 /1? A TTORNE Y.

Aug. 28, 1928. 1,682,077

E. P. GRAY AIR COOLED MUFFLER Filed May 8, 1926 2 Sheets-Sheet 2 INVENTOR. [M/VET f 4/? y ATTORNEY.

Patented Aug. 28,1928.

PATENT OFFICE.

EMMET P. GRAY, F DETROIT, MICHIGAN.

AIR-COOLED MUFFLER.

Application filed May'8, 1926. Serial No. 107,546.

This invention relates to mufliers for internal combustion engines, and an object of the invention is to provide an aircooled mufiier in which air may be taken into the interior of l the muflier to reduce the temperature of the gases passing therethrough from the exhaust manifold of the engine, and thus to reduce explosive effect and also prevent an overheating of the muffler structure.

An additional object of the invention is to provide a muffler of the character mentioned in which air passing into the muffler may be discharged to a heater for an automobile body with which the engine may be associated and thus secure a superior type of heater in that there are no highly heated parts, such as part of an exhaust conduit mounted in the floor of the body as is the usual practice, which discharges heated air into the vehicle body and thus provides a supply of heated fresh air free from odor. With the ordinary heaters in use involving partsof an exhaust conduit and usually mounted in a heater casing the heated pipes become covered with dirt and litter from the floor of the car and upon the heating of the pipes odors are developed which are objectionable.

With my improved type of muffler a source of supply of uncontaminated fresh air is provided particularly in View of the fact as is hereinafter more fully described that the air.

is taken into the muffler through a conduit or chamber closed to the gas channels and this heated air conduit within the muflier is not in position to accumulate dirt or matter of any descriptionthat would be productive of odor through the heating thereof.

It is a further object of the invention to provide a muffler head in which the exhaust gases are received and, by a plurality of channels, the said gases are dispersed in several directions practically transversely of the direction of flow of the gases through the muffler to be discharged into the muflier proper and finally to a tail pipe where it is discharged to atmosphere subsequent to being broken up into a plurality of streams cooled and the several streams all uniting to discharge to the tail pipe all as is hereinaftermore fully set forth. These and other objects of the invention are hereinafter more fully described and the pre ferred form of construction of a muflier embodying my invention is shown in the accompanying drawings in which- Fig. 1 is an illustrative view practically diagrammatic in form showing the application of the muffler to an automobile.

Fig. 2 is a longitudinal sect-ion of a mufiier embodying my invention.

Fig. 3 is a side elevation of the cast head of the muffler showing the course of'travel of the air .therethrough.

Fig. 4 is a section on line 4-4 of Fig. 2.

Fig. 5 is a section taken on line, 55 of Fig. 3.

Fig. 6 is a View similar to Fig. 4 showing an alternative arrangement of the valve control for the air conduit The -mufller construction, most clearly shown in Figs. 2 and 3, consists of a cast iron' head indicated generally by the numeral 1. This head has an aperture in its forward end to receive the exhaust pipe 2 from the engine, it being provided with a proper packing gland 3'. This head has a. large central chamber 4 at its forward end into which the gases are discharged and has a smaller central longitudinal passageway 5 open at its rear end to receive the discharge conduit 6. This conduit 6 may be fastened to the terminal end 7 of the said head by a pin 8 and there is provided a sheet metal member 9 secured in place by the pin 8 in the interior of the tube 6 closing the tube 6 to the conduit 5. There are also provided at this tail end 7 of the cast head a number of apertures 9 indicated by dotted lines in Fig. 2 and in full lines in Figf3 providing for a restricted flow of the gas from the tail .end of the conduit 5 into amuflier chamber 10 preferablycylindrical shell 11 integral therewith thus providing a chamber 12 about the conduit 5. There area number of ribs on the outer surface of the shell 11 indicated at 13,

14, 15 and 16 which are apertured for instance as indicated at 17 or are cut away at some portions as indicated at 78 in Fig. 5 fo r a purpose as will hereinafter be described. The cast Ull head has a chamber 18 at the receiving end extending about the chamber 4 and ribs 19 and 20 are provided on opposite sides of the chamber 4 which separate the chamber 18 into two parts indicated at 18*"- and 18 in Fig.4. There are also channels 21 and 22 openin respectively to the half chambers 18 an 18 and opening to atmosphere. as will be understood from Figs. 3 and 4.

The cast head is also provided with transverse channels 23 and 24 in diametrically opposite sides thereof and similar channels 25 and 26 on oppoi'ste sides at a right angle to the first named channels. These channels are similarly provided by walls 27 extending from the inner conduit 5 to the exterior encircling wall 11. The channels 23 and 24 are is also to be understood that the rib 20 is in continuationwith the walls forming the opposite passageway 24 and thus the walls of these channels 23 and 24 and the ribs 19 and 20 separate the chamber 18 practically into two half parts 18 and 18". The walls forming the channels 23 and 24 donot extend the entire length of the gas conduit 5 and thus there is a passageway about the inner ends of said channel walls between the half parts of these chambers. The apertures 21 and 22 are in communication with the respective half chambers as will be understood from Figs. 3 and 4 and thus air may enter the a lower aperture 22 and pass in the direction of the arrow shown in Fig. 3 about the end or walls forming the transverse passages 23 and 24 "and thence to the outlet 21. It is to be observed that this air passesfrom atmos phere into this interior. chamber 12 of the cast head and thence therefrom and this air may be guided, by means of a conduit 27, to the inlet port 22 and the outlet port 21 may be connected by means ofa conduit 28 with a heater element 29 all as is indicated in Fig. 1. By this means fresh air from the forward part of the vehicle may be taken through the mufiler and discharged into the body of the vehicle and in so passing cools the exhaust gases and reduces the explosive eflect thereof.

For what I have termed the muffler portion, I preferably provide an exterior sheet metal shell 30 which extends over the ribs 14, 15 and 16 and engages against therib 13 of the cast head and the channels 23, 24, 25 and 26 open through the shell 11 into the chamber 81 within this shell 30. It is also to be noted that the ribs 14 and 15 are apertured as indi I cated at 17 and are also cut away as indi-- 'cated at 78 permitting gases toflow from the forward end of the chamber 31 toward the additional sheetmetal shell 32 that engages a shoulder 33 provided at theinner end of the cast member and this shell is provided with a series of apertures 34, to permit the gases toflow-from the chamber 34 into the chamber 10 as heretofore mentioned and the asespass from this chamber 10 into the con d uit 6 which extends outwardly through a cast head 36. A tail pipe 37 is attached to the v I conduit 6 by means of a coupling 38threaded on the pro'ecting end of the tube 6. The head 36 is pro ded with a pair of circular ribs 39 I and 40 on which the shells 30 and 32 respectively are supported. 7 This member 36 is held in place by the coupling member 38 and in view of the'fact that the tube 6 is fastened to the terminal portion 70f the .cast head,'the tubes 30 and 32 may be forcibly seated against the rib 13 and 16 of the casting and the several parts thus tied together by means of the single. member 38. This arrangement provides for a ready disassemblyof the mufller parts forthe purpose of cleaning.

The inlet and outlet 22 and 21 respectively may be providedwith-the valve arrangement as shown in Fig. 4 or as is shown in Fig. 6. In Fig. 4 I have .shown a valve 41 and in the outlet channel 21 and a similar valve in the in.- let channel 22. These are the usual butterfly valves supported .on a vertical rod 43 operable by means of the lever 44 which may be connected by a cable (not here shown) to adjacent the drivers compartment of the vehicle. With this valve arrangement as shown in Fig. 4 the air flow through the muffler may be entirely cut ofl or it may be varied to any desired degree.

In view of the desired cooling effect that results from a flow of air through the mufller I preferably use the valve" arrangement shown in Fig. 6 in which is providedan outlet tube 45 having a terminal portion-46 that may be connected with the heater conduit similar to that shown at 28 in Fig. 1 and has occupy an'intermediate position .as'is indicated in dotted lines in Fig. 6. -With this arrangement the inlet channel 22 may be rovided with an inlet conduit indicated 2. 27

corresponding to the conduit 27 of Fig. 1 and preferably facing toward the forward end of the vehicle so that movement of the vehicle tends to force air into this inlet-tube 27* and thus through the heater. The tube 27 may be bellmouthed if desired. With this arrangement of valve control indicated in Fig. 6 the flow of air through the mufiler is at no time obstructed but the air that becomes heated in passing through the mufiier may be discharged-to the-heater or to atmosphere or to both as the operator may desire.

By the arrangement of parts-described a cast head is provided which may be termed a heater head and sheet metal mufiler parts are assembled therewith to receive the gases from the head and in much the usual manner break up the gas streams as they pass to the outlet conduit 6 of the mufiier. The cast head, as previously stated, is provided with an air chamber through the central portion of which and around the exterior of which heated gases flow, and air passing from the inlet to the outlet conduit is caused wto traverse longitudinally of the chamber from its forward to the rear end and thence back to the forward end. This distance of travel of air in flowing from the inlet to the outlet causes the same to become heated thoroughly due to the length of time it is within" the influence of the heated gases. This absorption of heat from the gases by the air flow through the heater portion of the mufller tends to materially'reduce the explosive effect of the gases and thus the gases are discharged to what is here termed the muflier portion-of the device under less pressure than is usual and therefore less bafiiing of the'gases in their flow is required to eliminate the successive exhaust impulses that exist in the gas stream as it enters thev device. In fact the 'nufiler portion of my de-- L vice is for the purpose of causing a thorough (ill intermingling of the gases of combustion which are discharged into the chamber 31 from the heater head of the mufier under successive exhaust impulses. By this arrangement I secure a muflier that is not productive of back pressure in the exhaust manifold to any material extent and secure a source of heat for heatin the car.

I am also ahle to secure a very simple 'mufiier that is of few parts and in which tie rods heretofore used are dispensed with which heretofore have been more or less unsatisfactory in use due to their becoming loosened and thus permitted to vibrate. By myarrangement the sheet" metal parts of the mufiler are forcibly held in position by the through this passageway and that the ap-' pended claims are to be so understood.

Having thus fully described my invention, its utility and mode of operation, What I claim and desire to secure by Letters Patent of the United States is- 1. A mufller comprising 'a substantially cylindrical head having a central cylindrical chamber, a cylindrical shell surrounding the central chamber and spaced therefrom providin g a ring like outer chamber, passageways leading from the central chamber to the ex terior of the outer shell, said passageways being formed by walls extending from the wall of the inner chamber to the wall of the outer chamber, ribs provided on opposite sides of the inner shell member separating the outer chamber into two parts, the said ribs being in continuation of the walls for said passageways from the central chamber and the said walls of the said passageways terminating short of the end of the said head and thus providing for communication between the two halves of the outer chamber, an inlet channel for one of the said halves at the forward end and a discharge channel for the other half and located at the said forward end, the said channels and outer chamber providing an air channel, a shell about the said head and into which the said passageways from the central chamber open, and a discharge conduit through which the gases flow from the interior of the said shell.

-2. Aanuflie'r comprising a head having a central longitudinal chamber and a surrounding-shell in spaced relation therewith, transverse passageways leading from the central chamberto the exterior of the outer shell, the space between the central chamber and outer shell providing a passageway for air, means at the forward end of the head for receiving an exhaust conduit, a, discharge conduit secured to the opposite end of the central chamber and closed thereto, a header mounted on the said discharge conduit, means on thesaid discharge conduit for drawing the header toward the said head, and an outer shell supported at one end by the header and at the opposite end by the said head, the said transverse passageways of the headdischarging into the outer shell, and the said discharge-conduit having an apertured wall to receive the said gases.

3. A muffler comprising a head adapted at one end for connection with the exhaust con duit of an internal combustion engine, a chamber therein for exhaust gases, an air passageway about said chamber, a plurality single member 38 acting as a nut to draw up of tubular sheet metal shells, the outer sheet the head 36 as heretofore described.

While I have described the passageway or chamber 12 as being an air passageway, it is to be understood that water or any fluid adaptable for heating purposes may be passed metal shell extending about the head, there being passageways from the central chamher to the interior of the said outershell, a discharge conduit in axial alignment with the central shell and secured thereto at one ,gas passageways leading to wit end, said discharge conduit being closed to tured walls permitting the gases disc arged.

into theouter shell to flow into the discharge conduit.

4. A mufller comprising a cast head, and a series of sheet metal shells providing a muffler portion, said head having an inner passageway for gases longitudinally;l thereof and in the outer of the said shells, a passageway for air about said inner passageway and closed to the gas passageways, a discharge conduit to which, the gases in the outer sheet metal shell flow, seats provided on the cast head for the ends of the sheet metal shells, a header for the opposite end of the shells, and means on the discharge conduit for drawing the header and the said cast head towards each other to tie the said head and shells together.

5. A mufiler comprising a cast head formed with two concentric chambers, the inner chamber providing a (gaspassa geway and the outer chamber pro'vi ing an a1r passageway, there also beingpassageways from the interiorchamber to the exterior of the head, a sheet metal shell positioned about the head into which the gas is discharged, the arrangement providing that the air passage- Way is surrounded by heated gases, apertured ribs on the head providing an internal support for the sheet metal shell intermediate its ends, a header for tlie said shell, a discharge conduit in axial alignment with the central chamber of the said head and-closed thereto, a header on thesaid conduit supporting the said sheet metal shell at one end, means on the cast head supportin the opposite end of the shell, and means or moving the said header to exert pressure on the said outer sheet metal shell maintaining the same in position. v

6. A mufiler for internal combustion engines comprising a. hea-d,an air passage therein arranged to cause a travel of air from the forward end to the rear end and thence again to the forward end of the head,-a central passageway for exhaust gases, and. ashell providing a chamber about the said head to which the exhaust gases are discharged whereby the it thereto, and the opposite end of which leads air passageway is surrounded by chambers for the heated gases, a discharge conduit to which the gases are finally discharged, and a valve for controlling the flow of air through the air passageway.

7. A muflier for internal combustion engines comprising a head having a passageway for exhaust gases and a passageway for air closed to the gas passageway, valve means for controlling a flow of air through the said air passageway, and a series of concentric shells "into which the gases are discharged trom the said head, the arrangement providing that the gases ass from an external to successive internal 5 ells and fromvthe central one of which the gases are discharged to atmosphere.

8. In a mufiler, a head having a central longitudinal chamber and a concentric outer shell providing a chamber thereabout, the

said last named chamber being divided by a wall extending the major portion of the length of theinner member providing two half chambers in communication. at the rear end, an inlet pdrt for one ofthe half-chambers at the forward end and an outletport for the other half-chamber also at the forward end, passageways .,for gas leading from the inner member to the exterior of the outer shell, and means for causing the streams of gases passing through the said last named passageways to from a single outlet. q

- 9. A mufller for, exhaust gases of an internal combustion engine consisting of a unitary structure having a cooling section and a mufiler section, said cooling section comprising a cast metalhead having separate pasair passageway including a chamber surrounding that part of the exhaust gas pasposed toatmosphere" and into which" the gases are discharged from the head, a header for the tubular members and shell, said cast e united and discharged sageways for exhaust gases and for air, the

metal head having seats for the opposite ends of the tubes and shell, and means for binding the header and the said head. p

10. A muflier for the exhaust gases of an internal combustion engine comprising a cast metal head having'a central longitudinal channel for exhaust gases and a separate concentric chamber thereabout through which air may pass, the central exhaust chamber having passageways discharging exteriorly of thepastmetal head, a silencing device ineluding a central tubular member supported at its inner e d. by the head and closed terior surface of which is exposed to atmos phere and through which exhaust gases from said passageways pass to the said central .the said tubular members and shell between tube, a header on the tube having a seat for the end of the shell, a seat on the cast metal head for the opposite end of the shell, means on the tube for forcing the header toward the cast metal head to forcibly support the shell against the seats.

11. In an automobile having an internal combustion engine, a conduit for the exhaust gases therefrom and a conduit for heated air discharging into the body of the vehicle, of a mufiler into which the exhaust gases are discharged, said muffler comprising a cooling section and a mufilcr section, said cooling section having separate passageways for the exhaust gases and for air, the air passageway discharging to the air conduit leading into the body, valve means in the said passageway adapted to cause the air to discharge to the body of the vehicle or to atmosphere, the mufller section including a silencing means through which the gases are passed to atmosphere, and a shell surrounding both the cooling and the mufiler sect-ions, the exterior surface of which is directly exposed to atmosphere and into which the gases are discharged from the head.

12. A mulller for internal combustion engines, comprising a cooling section and a mufiier section arranged in tandem, said cooling section having a passageway for exhaust ases and passages for a cooling medium adacent thereto, but closed therefrom to provide a ready transfer of heat from said exhaust gases to said cooling medium, but prevents intermingling of said gases and coolin medium, valve means associated with sai passageway for said cooling medium whereby said medium may be delivered to a plurality of openings in varied volume without restricting the flow of said cooling medium through said cooling section, said valve means being arranged to automatically close one of said openings while opening the other, said muflier section comprising a shell which is open to said gas passageway at one end and open to the atmosphere at another point, said shell at one end being supported upon said cooling section in axial alignment therewith and containing a muflling element and locking means between said muffler and said cooling section to maintain said section and shell in assembled relation as a unitary structure.

In testimony whereof I sign this specifi' tion.

EMMET P. GRAY. 

